24-70's poor quality control

[cactusclay]

Well, I just about gave up trying to get a sharp 24-70/2.8. I got one from B&H last week and about a sixth of the image was soft at all apatures and focal lengths-It went back with a copy of a full frame shot. I hate to complain about things, but I thought everyone should know about this, since this lens cost about twelve hundred bucks and the quality control should be quite stringent, in my opinion. I don't know how you get the attention of a large corporation, like Canon, but not buying their products might help. I did the test with two 1.6 crop bodies and the result was the same. Yesterday, I went to the city and tried two different lenses at two different stores, that's four 24-70 2.8's. Two of them were not much better than the one I sent back to B&H, softness on the sides, not the edges, which would have been acceptable, I guess, because a canon rep I talked to on the phone said that it was normal for twelve hundred dollar zoom lenses to be soft on the edges- I feel sorry for the people using full frame camera's, if that's the case. Anyway, like I was saying two were soft on one side or the other and two were soft in the middle at 2.8 and 3.5, at which point I stopped my test in discust. I thought there might be a chance it was the camera, but when I put a 85 and a 50 on, the image was sharp all over. I'm very envious of those of you that have sharp copies, apparently you are very lucky. Maybe I will find one someday. :rolleyes:

[tim]

I've heard the Tamron 28-75 has similar problems, but mine's very sharp.

[cc10d]

I too had the same experirnce with the 24-70 2.8L. I took the first one back, due to softness at 2.8 or poor focus, anyway the 2nd one they had at the store checked out similarly. So I decided if I had to stop down for sharpness, my 28-135 was fine for me. I have later picked up my only non canon lens the tamron spaf28-75f2.8XRDiLD Aspherical(if)macro. What an alphabet! Anyway without actually comparing side by side, my feeling is that it is as good or I think better optically as the Canons that I had and is a whole lot less investment. It at least is very usable at 2.8, and gets used.

[WestFalcon]

I sometimes wonder if some lenses seem soft because they are not calibrated correctly. I had a 130SF canon lens and it was sharp on one body and soft on another which in this case sounds like a body problem. There are a lot of variables so sometimes it is hard to know if it is the lens, body or maybe even the photographers shake at long focal lengths.
Of course it could be a soft lens too...takes a lot of careful testing and you can't do that in a store or on the internet. 10% restocking fees don't help either, since some places won't let u try them out.

[ed2day]

I've got a 24-70L coming in the mail, so of course I'm a little nervous when I hear these stories. Just to be fair, I'll point out that cactusclay also had to try three 50mm 1.4's to find an acceptable one. I don't mean to criticize, just some people are more choosy than others. That's certainly their perogative. I will say that in the dozens of 24-70L bad copy horror stories I've read about I've yet to see a "bad" example posted, so it's hard to know what people are seening. If I don't feel my 24-70L is usable at 2.8, I'll be very disappointed. Maybe come Tuesday, I'll be complaining too. Sure, there's manufacturing tolerances in lenses ($1200 ones too). On most of my lenses I can see one side is better than the other if I look closely. I think part of the problem is what has traditionally been the standard for acceptable sharpness has been a 35mm film capture enlarged to 8x10. When you start looking for sharpness in 100% crops, that's equivalent to a poster-sized picture and sets a much more stringent criteria.

[Tom W]

Maybe I'm lucky, but my 24-70 has performed very well on the 10D, 1D Mk II, and the Elan II. I'm certainly not going to give it up!

Westfalcon has a point - both the lens and camera can be calibrated, and sometimes, they don't quite work well together. I had a Sigma lens that worked perfectly on my 10D, but insisted on backfocusing on my 1D2. I sold it rather than getting it calibrated, but it was a hard decision.

[cactusclay]

I have to say that I am now of the mind that most of the autofocus lens now days are sort of slopped together in mass production and with the ever increasing population of people and photographers it has become too difficult to have any sort of stringent quality control. I've heard there was sample variation on the 50/1.4's and that some people's are sharp at 1.4 and some not till they get up towards 2.0. Well I have now discovered first hand that that is exactly the case, so if it happens with 50's and 24-70's then it can happen with -and I'm sure it does-all lenses. Futhermore, I also checked out a 24/2.8 at one of those stores and found that it was not in the slightest way sharp at 2.8. I know it sounds as if I'm picky, but in reality, I just want to offer my customers the best quality that I can afford and to settle for something less than what I'm paying for, seems to be nothing short of laziness on my part. If you have a choice on a sharp lens wide open and a soft one, which would you choose?

[cactusclay]

Upon closer inspection, of my thoughts, I have to say that maybe I am picky after all, but it's my money and I can be picky if I want to.

[Tom W]

Upon closer inspection, of my thoughts, I have to say that maybe I am picky after all, but it's my money and I can be picky if I want to.

There's nothing wrong with being picky. Your clients deserve excellent results. Just remember that when you look at an image on-screen at 100% crop, you're looking at something that is the equivalent of a 20X30 inch poster, or larger, from 10-20 inches away. You're going to see things that would not show up in a 11X14 image.

[Tom W]

I have to say that I am now of the mind that most of the autofocus lens now days are sort of slopped together in mass production and with the ever increasing population of people and photographers it has become too difficult to have any sort of stringent quality control. I've heard there was sample variation on the 50/1.4's and that some people's are sharp at 1.4 and some not till they get up towards 2.0. Well I have now discovered first hand that that is exactly the case, so if it happens with 50's and 24-70's then it can happen with -and I'm sure it does-all lenses. Futhermore, I also checked out a 24/2.8 at one of those stores and found that it was not in the slightest way sharp at 2.8. I know it sounds as if I'm picky, but in reality, I just want to offer my customers the best quality that I can afford and to settle for something less than what I'm paying for, seems to be nothing short of laziness on my part. If you have a choice on a sharp lens wide open and a soft one, which would you choose?

The fit and feel of lenses today is definately not what it was 20+ years ago. That smoothness of the focus ring, and gentle click of the aperture ring are desirable traits that no longer exist. Even the "L" lenses don't feel quite that good.

Yes, there are tolerances from copy to copy. I suspect that those tolerances tighten up with more expensive glass, but they still exist, and as long as a lens falls within the acceptable limits, it will be sold. The rejection rate of wanting perfect glass would be enormous. That's why Leica gets upwards of $3000 for 28 mm primes.

There's also variance among people's expectations. My 50/1.4 is pretty sharp at f/1.4, but I wouldn't expect it to be tack sharp nor as contrasty and colorful as it is at f/2 or higher. That's a physical characteristic of optics. I don't expect that, but I do expect it to deliver useable images wide open. It does.

[cactusclay]

I hear you Tom and I agree, but I'm not talking about 100% crops, I'm talking about being able to see things at the 5x7 level, in fact I could see some softness on my lcd with no magnification on one of the 24-70's, right dead center.

[Tom W]

I hear you Tom and I agree, but I'm not talking about 100% crops, I'm talking about being able to see things at the 5x7 level, in fact I could see some softness on my lcd with no magnification on one of the 24-70's, right dead center.

On the LCD? On the back of the camera? It would have to be totally out of focus to see it there.

[cactusclay]

Don't take my word for it, by all means go and try it for yourself.

[Tom W]

Don't take my word for it, by all means go and try it for yourself.

I have the 24-70 - its very sharp at 100% on the computer, let alone on a 230,000 pixel LCD.

But I've never been able to see an image clearly enough on the LCD to tell if a lens isn't sharp, unless its very out-of-focus (like I left the AF off). The viewfinder is a much better tool for seeing image quality than the LCD, and even it isn't big enough to see very much.

[cactusclay]

You have a 24-70, not the 24-70, and I'm very happy that you have a sharp one, but rather than question what I'm saying, which is just fine with me, but for your own knowledge, you may want to go to a store and try some others, just to see what you come up with. Who knows, maybe I'm talking out of my @rse, but at least I went and tried for first hand experience. Nothing worse in my mind than contempt prior to investigation.

[Tom W]

I'm not disagreeing that you've seen your share of bad copies - I'm just wondering how you can see that problem in the tiny LCD on the back of the camera. For me, its only use is to quickly check composition and view the histogram.

[SDK^]

On the LCD? On the back of the camera? It would have to be totally out of focus to see it there.
Yeah he's right.
If the image looks soft on the LCD on the camera then the photo is completely out of focus.

[cactusclay]

Wrong. Zoom in with a 70mm lens on a phone book page, get as close as you can, so you can still aquire your green light of focus, or focus manually. You know what just forget the whole thing. My intention was not to start an argument. I was just sharing my experience with the people on this forum. It may be a disturbing experience, but experience non the less. I guess the only way to find out if it is worth taking note of is to go out and try it for yourself, rather than just say no, that won't work, that's wrong or that's acceptable. Some people are extremely comfortable in their ignorance-I'm not one of them.

[cc10d]

Cactusclay, you are not the only one who has been disappointed with some copies of the 24-70. There are many reports like yours. funny most of our other lenses are OK but we just pick on this one, huh? the copies I tried were ok stopped down, but that isn't what I bought a 2.8 lens for. I use other 2.8 lenses without dificulty at 2.8. interesting..

[eosster]

I have this lens and have no such problem, maybe I am one of those lucky people.

[SeanH]

I have posted before about how unhappy I am with this lens, I'm on the third one and I am still not happy.......at least for the cost of this lens. Love my 17-40, and my 70-200 2.8 is razor sharp..........and so are a few of the shots with the 24-70 2.8, but many more photo's are not sharp compared to my other 2 L's. I'm either going to sell it and get the 10-22 & 28-135IS, or send it too Canon to have them check it out.

Bottom line……IMO.... this is a VERY inconsistent lens, made worse by the cost of it.

[Mike H]

How can one "try a lens in the store" and judge its image quality? Thanks.

[raylks]

I am quite surprised that Canon has a much more variation in producing 24-70mm lens than the other lenses.

The reason that I trust Canon quality L lens is its consistency in rolling out sharp and accruately-focusing lenses. What you all are telling me is very strange: Canon is having a problem in assuring the quality on one particular lens instead of all other lenses.

I have the 28-70mm L, which are regarded inferior than the 24-70mm L but luckily, mine is a good copy.

[cactusclay]

To try a lens in a store, you might want to call ahead and ask if they mind, that's what I did and they said sure. Take a tripod a camera and a clipboard with newsprint or a page out of a phone book. Find a place to lean the clipboard and make sure the lens is paraelle to it. You can then get an idea-contrary to popular beleif- by zooming in on your LCD screen. I did this and got the same results as I did when I put on my computer at home. Also I don't belive that the problem is with just the 24-70 2.8 lens. Like I said earlier, I tried three 50/1.4, before finding one that was half way sharp at 1.4 and I also tried a 24 2.8 that was not sharp in any sense of the word at 2.8 This leads me to believe that a good portion of the lenses on the market are sub standard and that is why I suggested on another thread that some other people make a simular experiment and let the rest of us know what they find.

[cactusclay]

I think the reason we hear so much about the 24-70, is because it cost so much and when most people spend that much on a lens, they check it out. Most pro's do anyway, but when there is a lot on the line, we tend to pay closer attention.

[Tom W]

Are you using a tripod? Keep in mind that wide open, your DOF is razor thin. Any movement after focus lock, even 1/4 inch can affect your sharpness quite a bit.

[cactusclay]

Ten four, and the on board flash to freez any movement, as well as locking up the mirror.

[HKFEVER]

Hmmmmmm.:confused:

This is the first time I heard about the softness of this 24-70 f/2.8L.

But, I am sure it can't compare to 135mm or 100mm marco. But overall, it is excellent. In HK, we treasure these 3 Zooms, 16-35 f/2.8L, 24-70 f/2.8L & 70-200 f/2.8L IS.

They meet the daily use range.

[ed2day]

Hey Cactus,
Sorry if I put you on the defensive. It sounds like you've given the lens a fair shake and if it's not accptable for your purposes, then it's not acceptable. I'm curious though--did you test to see if it was a focus problem i.e. is it sharper with manual focus? Like I said, I'll see with mine when it gets here this week. I just love the pictures I see with this lens. It has qualities that go beyond just resolving power.

[cactusclay]

I did test the focus by first using AF, then adjusting manually there was no difference, the lenses focused perfectly.I have 20-20 vision and I can tell when something is in focus, just like I can tell when it is not. I printed up a copy of a full frame shot I took with the one I sent back to B&H. I had over a hundred shots on my computer that I took over the past few days and deleted them yesterday, I wish i would have saved them now. I think people are having a hard time believing this, so like I suggested earlier, why don't some of you other people go to a store and do some tests of your own. Maybe both my cameras are bad and all my good lenses are bad as well and just look good on my bad cameras. Maybe I did something wrong in the tests, I'm open to that, I was wrong once before-ha ha.

[HKFEVER]

Check these out, only re-size:
1st one 2.8 70mm
2nd one at 5.6 70mm

[HKFEVER]

Check these another 2, only re-size:
1st 5.6 24mm
2nd8.0 24mm

[Mike H]

...You can then get an idea-contrary to popular beleif- by zooming in on your LCD screen. I did this and got the same results as I did when I put on my computer at home. ...

I guess we'll have to agree to disagree on this one. There's no way that looking at a low resolution JPG on the small, low resolution screen on the back of a camera is a fair criteria for rejecting a lens. Regarding using your computer screen at home, there are problems with doing it that way, too. I suppose that there's no point in going into that.

I suspect that using your method you will be able to successfully examine and reject many lenses from every manufacturer. As an alternative, you may wish to try printing out these test shots, preferably at your maximum required print size, and judge that way. Isn't a print the normal output that you'll be concerned with?

As my academic friends like to say, before testing any subject you first have to develop a method of testing the testing method. For what it's worth, they call it verifying a test's internal validity.

Mike H

[Tom W]

I guess we'll have to agree to disagree on this one. There's no way that looking at a low resolution JPG on the small, low resolution screen on the back of a camera is a fair criteria for rejecting a lens. Regarding using your computer screen at home, there are problems with doing it that way, too. I suppose that there's no point in going into that.

I suspect that using your method you will be able to successfully examine and reject many lenses from every manufacturer. As an alternative, you may wish to try printing out these test shots, preferably at your maximum required print size, and judge that way. Isn't a print the normal output that you'll be concerned with?

As my academic friends like to say, before testing any subject you first have to develop a method of testing the testing method. For what it's worth, they call it verifying a test's internal validity.

Mike H

Mike, you raise a really good point - we seem to suffer from the curse of the 100% crop. It's OK to test one lens against another at 100% on the screen, but it needs to be kept in mind that you're looking at the equivalent of something on the order of 45 X 30 inches, depending on pixel count, screen size and resolution. You're not generally going to get quite the results that the typical 11X14 print would produce.

I'd be interested in working to develop a simple, standardized test methodology for checking lenses quickly that eliminates as many outside influences as possible, but allows for testing of sharpness, contrast, color, and other characteristics of a lens without leaving the store (assuming that there is a store nearby - we don't have one here in town that I know of). I think a lot of the variation that we see on the 'net is simply the variations that occur when test methods aren't the same. Some shoot brick walls, while others shoot newspapers. Some shoot in direct sunlight, while others use high ISO and others still use hot lights, flash, or strobe.

And of course, there's the issue of camera shake, movement, and such.

Some people just go out and shoot barns on dull, overcast days, and others shoot the parking lot out in front of the shop. While all of these tests will tell us something about the lens, none are capable of being used to compare one lens against another.

[Mike H]

Agree, Tom.

That kind of rigorous testing control is what the people on Photodo.com were apparently doing. It's too bad that--for whatever reason--they've stopped testing lenses. Dpreview.com tests cameras in a way that seems quite good; I wish they would undertake lens tests as well.

Mike H

[Tom W]

Photodo definately did good lab tests, and they were valid at least for the sample that they used. Popular Photography mag, for all its faults, has a fairly reasonable lens test - their results seem to match my experience quite well. It is a shame that they don't allow the space to give more in-depth data though.

What I'd like, though, is to work on getting together a battery of simple tests that we users could do in a standardized way to determine relative quality and to do quick evaluations of lens qualities. Its just so hard to make an objective, standardized test that is quick and easy to perform. Still, a well-designed subjective test, along with data from various sources is better than nothing.

Ideally, I'd like to bring a lens home and spend 1/2 hour to 45 minutes running it through a battery of tests to determine its capabilities with some degree of accuracy. I'd rather spend time using them then testing them, but I also want to make sure that my money is well-spent.

[Mike H]

... Ideally, I'd like to bring a lens home and spend 1/2 hour to 45 minutes running it through a battery of tests to determine its capabilities with some degree of accuracy. I'd rather spend time using them then testing them, but I also want to make sure that my money is well-spent. ...

In some ways that would be more useful than the Photodo.com tests. As you mentioned, they did good tests of the samples that they received, not a sampling of many lenses of the same model. They might have gotten a very good or bad sample of whatever lens they were evaluating, leading us all to believe that a particular lens was better or worse than the typical purchaser should expect. Nothing is perfect.

A test that we could do and be confident of would give us a chance to check the lens that matters to each us the most: the lens that we spent our money on.

Mike H

[cactusclay]

Ok, Mike and Tom, let me ask you both this. If you take pictures of newsprint or phone book pages and the lens is lined up level with the subject, then you look at the letters and all are sharply defined, except in certain areas, you do it again at different apatures and focal lenghts and you get the same out of focus areas, then you try another lens and find different areas out of focus, you cant beleive your eyes, so you go back to the first lens and the same areas still have letters that are not in focus, what does that lead you to believe?

[Tom W]

Are these out-of-focus areas corners, or specific parts of the page that you're photographing? Is the subject perfectly flat, or does it have lumps or wrinkles in it? That shallow DOF can hurt you. Here's an image I took with my 300/4 at f/5.6 (granted, its a 300 mm lens, but it illustrates the situation well):

Click here (http://www.pbase.com/photosbytom/image/38177324)

Click on "original" to see the full-sized image. Note how shallow the DOF is, even at f/5.6. The line of dust on the table illustrates that well.

[cactusclay]

Well, I would have to be a complete idiot to take wrinkled subject matter to test out a lens that I really want to own and have now spent close to sixty bucks for expences in the pursuit of one.Then I would have to be an even bigger idiot to come back home and tell all you fine people that I just tested a bunch of lenses with wrinkled out of focus subject matter. Shooting a battery with a 300 and showing how it very quickly goes out of focus doesn't show if a lens is sharp all over. Shoot some newsprint and see what happens. The 24-70 has a macro mode as limited as it may be it is there. I should be able to shoot pictures of print with the entire image in focus, save for the edges, acording to canon. If a 400.00 85 mm lens can do it, why can't a 1200.00 one.? I know this thread is getting rather long, but I did mention earlier, I believe that the one I got from B&H was soft in the bottom right. If you were to divide the frame in half horizontally, then into thirds, you would then have six equal squares. Well, one complete square in the lower right was totally out of focus on the one I got from B&H. I really wanted to keep that lens and I hoped that I had done something wrong, but after a few hours of checking and rechecking I discovered it was in fact the sad truth. While doing all those tests, I learned a few short cuts, that produced the same results, one of them was that what I saw out of focus on my computer, could also be seen out of focus on the LCD screen. The exact same area, so if that smashes some peoples mythology, you have my condolences.

[cactusclay]

Oh, by the way, as I stated earlier, I did make a print from the first lens, which by the way, showed the out of focus area in the exact same places as my LCD screen on the camera and my computer screen showed. I sent that back with the lens to hopefully deter B&H from sending it out to any other poor soul.

[Tom W]

Well, I would have to be a complete idiot to take wrinkled subject matter to test out a lens that I really want to own and have now spent close to sixty bucks for expences in the pursuit of one.Then I would have to be an even bigger idiot to come back home and tell all you fine people that I just tested a bunch of lenses with wrinkled out of focus subject matter.

Don't be so hard on yourself :) - We're looking for reasons here, not blame. How do you keep your open phone book flat? Setup is very particular here - if the lower righthand corner is slightly closer or farther from the lens, it will be softer.

Shooting a battery with a 300 and showing how it very quickly goes out of focus doesn't show if a lens is sharp all over. Shoot some newsprint and see what happens.

Nor is it supposed to show if the lens is sharp all over - it was to illustrate the shallow depth of field that can affect your testing. We're using the process of elimination here - eliminating the testing flaws that are common and trying to determine why you're finding all the bad ones. The plane of focus must be perpendicular to the center line of the lens. This needs to be very exact if your depth-of-field is very shallow. And at 70/2.8, it is roughly 1/2 inch.

I've messed this up myself a few times. Setup is critical.

BTW, I've shot plenty of newsprint. But, edge-to-edge sharpness problems are more prevalent in wide lenses, since its harder to correct for the various curvatures, not only barrel distortion but field curvature.

The 24-70 has a macro mode as limited as it may be it is there. I should be able to shoot pictures of print with the entire image in focus, save for the edges, acording to canon. If a 400.00 85 mm lens can do it, why can't a 1200.00 one.?

The 85 has two advantages - one, its a prime, and second, its a telephoto. Much easier to get a flat field on a tele than a wide, and on a prime as opposed to a zoom.

I know this thread is getting rather long, but I did mention earlier, I believe that the one I got from B&H was soft in the bottom right. If you were to divide the frame in half horizontally, then into thirds, you would then have six equal squares. Well, one complete square in the lower right was totally out of focus on the one I got from B&H. I really wanted to keep that lens and I hoped that I had done something wrong, but after a few hours of checking and rechecking I discovered it was in fact the sad truth. While doing all those tests, I learned a few short cuts, that produced the same results, one of them was that what I saw out of focus on my computer, could also be seen out of focus on the LCD screen. The exact same area, so if that smashes some peoples mythology, you have my condolences.

I had a Sigma prime that had problems on the entire right side, so that issue isn't unusual. It does warrant replacement, though. I'm still surprised that you keep finding all the bad ones.

[cactusclay]

Actually Tom at 70 mm, that would make it a short tele. I did find a good 50 mm, so all was not lost. If you tape the bottom of the page and clip the top in a clip on the clip board it makes it flat, but first tare the page out of the phone book, I would hate for someone to try testing a lense with the page folded over, still attached to the book that was not flat, for that would probably take more pages to explain than this has.

[Tom W]

Actually Tom at 70 mm, that would make it a short tele. I did find a good 50 mm, so all was not lost. If you tape the bottom of the page and clip the top in a clip on the clip board it makes it flat, but first tare the page out of the phone book, I would hate for someone to try testing a lense with the page folded over, still attached to the book that was not flat, for that would probably take more pages to explain than this has.

OK, so you're just using pages out of the phone book clipped flat on the clipboard (I hope you aren't married, or at least have another phone book). How do you set it up so that it is perfectly perpendicular to the lens axis?

Did you only test the lens at 70 mm?

[Mike H]

... If you were to divide the frame in half horizontally, then into thirds, you would then have six equal squares. Well, one complete square in the lower right was totally out of focus on the one I got from B&H ... While doing all those tests, I learned a few short cuts, that produced the same results, one of them was that what I saw out of focus on my computer, could also be seen out of focus on the LCD screen.

Out of focus, or not sharp due to lens aberrations? If you can see a lack of sharpness on the camera monitor then it's likely that the lack of sharpness comes from how you're setting up the shot, rather than from poor lens performance. I've used the D30, D60, 10D, and 1DM2, and none of them had sharp enough monitors for me to check critical focus, let alone tell about the subtleties of whether a lens was sharp in the corners.

Phil Askey (of Dpreview.com) recently pointed out that the latest monitors--which have greater resolution and allow for higher magnification--are much better for checking sharpness than the older ones. Yet there are times that a shot looks sharp on the camera monitor and then turns out to be not so sharp when I get it onto the computer or print it out. I can see the opposite happening as well.

As I said before, the final print is my main criteria for satisfaction. The final print is what the accountants might call "the net net".

Mike H

[Andy_T]

Cactus,

could you post one of your test shots.
I am really curious now :D

Best regards,
Andy

[data1ore]

It seems everyone talks about sharpness for QC for the 24-70, but no one mentions the red fringing problems this lens seems to be plagued by. Does anyone have any experience/comments on this aspect?

[ed2day]

Got my new 24-70L today. Just had time to do a quick test shot of the lawn from about 4 ft. away. Definitely softer at 2.8 (as all my lens are wide open), but I don't know if its a problem for me. I see no difference with a 5x7 image. At 8x10 I can discern a little difference that can be remedied with a very slight USM application. My initial take is I'd be hesitant to go larger than that at 2.8. For me I don't think that will be a big deal. But yeah, for the money I'd like to see a little better. The sharpness at 4.0 was magnificent (limited by 300D resolution). I guess it's time I learned to post some pictures. I'm headed for Mazatlan Sat. (haven't decided if I'm taking the 24-70)so don't know if I can find the time.

[data1ore]

Can those who've not done this before do this?

Shoot a high contrast photo (eg, shoot window blinds from indoor, with bright skies, so that the resultant pic is mostly black/white, or shoot the chrome of motorbikes and cars and catch the sun off the chrome, or a white fence) and watch the edges of the high contrast region for a distinctive red fringing.

I'm just wondering how many of you guys who think you have sharp copies have copies that are free of this red fringing problem.

[cactusclay]

Try shooting a flat phone book page at 70mm, making sure the camera is paraelle to page, get as close as you can and see what it looks like. use a tripod and your flash,even lock up the mirror if you can.